Many industrial processes involving procedures such as film deposition or coating on various products must be performed in a vacuum chamber. The presence of water vapor prevents the achievement of the vacuum level required and also creates problems for the production vacuum coater which are well known. Vapor slows the pumpdown to processing levels, affects adhesion, loads mechanical forepumps, and also dissociates into oxygen and hydrogen. Both gasses adversely affect films.
In prior refrigeration systems, fast cycle water vapor cyropump devices utilizing a fixed "Meissner" coil have been provided for use in vacuum chambers as disclosed in U.S. Pat. Nos. 4,535,597 and 4,597,267 which are assigned to the assignee of the present application. In the devices described in the aforesaid patents, a fixed "Meissner" coil, installed in a vacuum chamber, receives supercold fluid to provide cryopumping of water vapor after the initial rough pumpdown phase and during a high vacuum pump phase of the operation cycle. For a subsequent defrost cycle, heat is derived from a hot refrigerant gas stream controllable by apparatus external to the vacuum chamber. One disadvantage with the prior fast cycle "Meissner" type cyropump devices, as described, was that they required a fixed installation of a coil having the "Meissner" surface within the vacuum chamber. Such installations were generally complicated and therefore time consuming as well expensive to install. Also, with a fixed cryopump coil within the vacuum chamber, the space available for different types of production coating equipment was limited, thus making it difficult to accommodate changes in equipment within the vacuum chamber.
To overcome the problems and limitations of the fixed fast cycle cryopumping devices, the present invention provides a flexible fast cycle probe that can be installed with relative ease and minimal time within a simple pass-through a single port in the wall of the vacuum chamber. Being flexible, the probe can be moved and configured in any desired manner within the vacuum chamber to avoid interference with coating apparatus or other equipment or fixtures within the chamber, while being completely temperature controlled from outside the chamber.
Another problem which the present invention has solved is the elimination of undesirable noise in the flexible probe due to the flow of gasses through it during its operation cycle.